Based on measurements taken (more info below), I used three remnants:
seersucker, yellow shirting, and a soft white cotton
Elastic (hairband used here)
Thread and other assorted sewing goodies
A note about measurements: I made this dress out of the most basic of shapes: rectangles. Because I did not tailor this bodice to curves, it is a boxier look with a slightly open back. Feel free to modify any bodice information to suit your own personal needs/taste. I measured my daughter's chest, waist, and shoulders front to back. Don't forget to add seam allowance before cutting!
The following numbers are for my 5 year old daughter:
FRONT BODICE: cut 2 on fold 6.5"W x 8.25"L
BACK BODICE: cut 4-6.5"W x 8.25"L (NOTE: increase width by about an inch to avoid gap in back)
STRAPS: cut 2-4.5"W x 8"L
BELT: 6"W x 26"L
SKIRT: on fold 22.5"W x 12.75"L (about double her waist measurement for gathering)
Okay. You should now have various colors of rectangle in 10 pieces. So ready? Great! Let's sew!
Begin with your shoulder straps. With right sides together, iron them in half lengthwise.
Sew up the sides of each strap, leaving ends open. Rotate seam to the middle, and iron seam open. Turn strap right side out, and re-iron, with the seam placement still in the middle of the strap.
For a finished look, topstitch the edges of each strap.
Measure your child from center of armpit to where you want your strap to fall. On my daughter, this was 2.75" in from the side seam of the bodice. Pin your straps in place on the right side of your top bodice piece (with center seam facing UP). With right sides together, pin your second bodice piece into place, sandwiching straps in between the two bodice pieces. Sew bodice across the top, leaving sides and bottom open. Iron seams, flip right side out and re-iron.
(in some of the following pics, you will see I top stitched my bodice pieces before joining front and back. I recommend waiting until front and back are joined at side seams for a more polished look. Whoops.)
And speaking of whoops, I forgot to add my elastic in these next pictures, and that resulted in some mild frustration and frantic seam ripping. So do as I say, not as I...picture. Or don't picture, as the case may be.
For your back bodices, pin the other side of the straps to the right side of your two outer back bodice pieces, seam up.
Pinch your elastic so that there is one large loop that will work with the button you have picked out. Pin loop in place with the large loop facing IN. Pin the remaining two back pieces on top of the straps, right sides facing in. This should sandwich each strap and elastic. Pin across the top and down the inside of the pieces, and sew.
Clip corners, iron seams, turn pieces right side out, and iron again. You should now have a front and a back that looks something like this (sides still open):
Your bodice is now lined, with right sides of fabric out on both the inside and outside. So flip your bodice so that it's inside right sides are now facing out. Pin up the sides and sew using either a serger or other finishing stitch. If you don't have this option, sew up and cut with pinking shears, or use a zig zag stitch to create a more finished look. Topstitch the length of the top of the bodice, back side to back side.
You have a bodice (with an open back), hurray! Okay, onto the belt! Take your belt fabric, and iron it in half lengthwise, WRONG sides together. Open up your bodice and pin the folded side to outer right side of your bodice. The raw edge should be facing up, pointing towards the top of your bodice.
Sew the belt to the bodice. When you are done, iron your seams, pressing the yellow seam UP towards the inside of the bodice. Note that because your back is open, there should be some yellow belt that sticks out beyond each back edge (unless you've modified your measurements). Topstitch along the bodice above the belt for a more finished look.
Still with me? We're almost finished now! We'll begin with our skirt hem. Take your skirt piece, and fold up .25", ironing as you go. Repeat the process, this time folding up .5". Sew hem into place.
Run a gathering stitch across the top of your skirt. Lay it out against your belt/bodice piece, and gather so that it matches up with the belt piece. Pin onto the raw edge of the belt, with right sides together, hem facing towards the top of the outer bodice. Sew the skirt to the belt, using any finishing technique that works for you. (Sorry about the lack of picture, this was the time I was juggling a toddler who was up from a nap and demanding milk while desperately trying to finish the skirt portion.) When you're done sewing the skirt on, iron the seams, then press the raw belt seam down.
Topstitch the belt to the top of the skirt. (I topstitched on the skirt side, because I didn't have yellow thread. If you think it would look better, you could certainly topstitch on the belt side of your skirt.)
Pin your skirt sides and belt sides together, sew up the back with a finished stitch, and you're done! You have made the Gigi Dress!! Attach your button, dress your daughter, stand back and admire your handy work!
Dress up the bodice with a matching pin, and accessorize with a bright headband and some shades, and you're good to go!
I hope you enjoyed this tutorial. Again, please leave feedback! I'd love to do this again, and all comments will be much appreciated!